THE AMERICAN NATURALIST, An Illustrated Magazine OF NATURAL HISTORY. EDITED BY E. D. COPE AND J. S. KINGSLEY, ASSISTED BY DR. C. O. WHITMAN, DR. C. E. BESSEY, H. C MERCER, PROF. C. M. WEED, VOLUME XXX. PHILADELPHIA, U. S. A. THE EDWARDS & DOCKER CO., 518 & 520 MINOR STREET, Jm The Formulation of the Natural Sciences. E. D. COPE........... Some Localities for Laramie Mammals and Horned Dinosaurs (Illus- ......... The Bearing of the Origin and Differentiation of the Sex Cells in Cymatogaster on the Idea of the Continuity of the Germ Plasm. The Probable Influence of Disturbed Nutrition on the Evolution of Progress in American Ornithology, 1886–1895. R.W. SHUFELDT......... The Path of the Water Current in Cucumber Plants. E. F. SMITH. 372, 451, 554 On the Mississippi Valley Unionidæ Found in the St. Lawrence and A New Factor in Evolution. J. MARK BALDWIN Extensive Migration of Birds as a Check Upon the Production of Geo- graphical Varieties. T. H. MONTGOMERY.......................... |